Non-payment of bills for water services has become a major problem to the service providers. Consequently a number of inventions have been propagated in an attempt to provide a way of supplying these services on a pre-payment basis.
A number of these systems involve the purchase of tokens which are then inserted into a device which activates the supply point on the consumer's premises.
Unfortunately, persons have found methods of duplicating or simulating the tokens used or tampering with the device at the supply point. It is therefore an object of this invention to provide a system which overcomes these problems.